Numerical analysis on seismic response and failure mechanism of articulated pile–structure system in a liquefiable site from shaking-table experiments

This study investigates the seismic response and failure mode of a pile–structure system in a liquefiable site by employing a numerical simulation model combined with the shaking-table results of a soil–pile–structure dynamic system. The pile and soil responses obtained from the numerical simulations agreed well with the experimental results. The slopes of the dynamic shear-stress-shear-strain hysteretic curves at different positions also exhibited a decreasing trend, indicating that the shear strength of the soil in all parts of the foundation decreased. The peak acceleration of the soil and pile was not clearly amplified in the saturated sand layer but appeared to be amplified in the top part. The maximum bending moments appeared in the middle and lower parts of the pile shaft; however, the shear forces at the corresponding positions were not large. It can be observed from the deformation mode of the pile-group foundation that a typical bending failure is caused by an excessive bending moment in the middle of the pile shaft if the link between the pile top and cap is articulated, and sufficient attention should be paid to the bending failure in the middle of the pile shaft.